Pharmacology and Drug Interactions
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Questions and Answers

What is the primary mechanism of action of aspirin in relation to platelet aggregation?

  • Inhibition of platelet activation
  • Reversible inhibition of thromboxane A2 synthesis
  • Stimulation of thromboxane A2 synthesis
  • Irreversible inhibition of thromboxane A2 synthesis (correct)

What is the effect of aspirin on gastric mucosa?

  • It protects the gastric mucosa from irritation
  • It stimulates the production of gastric mucus
  • It irritates the gastric mucosa, causing epigastric distress (correct)
  • It has no effect on the gastric mucosa

What is the effect of long-term intake of large doses of aspirin on clotting factors?

  • It stimulates the production of vitamin K
  • It has no effect on clotting factors
  • It decreases the synthesis of clotting factors in the liver (correct)
  • It increases the synthesis of clotting factors in the liver

What is the duration of aspirin's effect on platelet aggregation?

<p>About a week (B)</p> Signup and view all the answers

What is the therapeutic effect of aspirin in analgesic doses?

<p>Only analgesic and antipyretic effects (A)</p> Signup and view all the answers

What is the effect of aspirin on bleeding time?

<p>It increases bleeding time (B)</p> Signup and view all the answers

What is the pharmacological action of salicylic acid released from aspirin?

<p>Analgesic, antipyretic, and anti-inflammatory actions (A)</p> Signup and view all the answers

What is the effect of prophylactic vitamin K therapy on bleeding risk associated with long-term aspirin intake?

<p>It decreases the bleeding risk (A)</p> Signup and view all the answers

What is the limiting factor in the absorption of aspirin?

<p>Poor water solubility (B)</p> Signup and view all the answers

What is the plasma half-life of aspirin, considering its conversion to salicylic acid?

<p>3-5 hours (B)</p> Signup and view all the answers

What is a rare but serious adverse effect of aspirin in children with viral infections?

<p>Reye's syndrome (D)</p> Signup and view all the answers

What is the result of salt and water retention caused by aspirin?

<p>Electrolyte imbalance (D)</p> Signup and view all the answers

Which of the following is a therapeutic effect of NSAIDs?

<p>Analgesia (B)</p> Signup and view all the answers

What is the characteristic of hypersensitivity reactions to aspirin?

<p>Idiosyncratic and infrequent (C)</p> Signup and view all the answers

What is the syndrome caused by anti-inflammatory doses of aspirin?

<p>Salicylism (D)</p> Signup and view all the answers

Which of the following is a characteristic of COX-2 inhibitors?

<p>Less gastric mucosal damage (D)</p> Signup and view all the answers

What is the most common age group affected by acute salicylate poisoning?

<p>Children (C)</p> Signup and view all the answers

What is a possible adverse effect of NSAIDs on the CNS?

<p>Seizure precipitation (C)</p> Signup and view all the answers

What is the outcome of long-term therapy with high-dose aspirin?

<p>Insidious onset hepatic injury (A)</p> Signup and view all the answers

What is the primary mechanism of action of nonsteroidal anti-inflammatory drugs?

<p>Inhibition of COX-1 and COX-2 enzymes (C)</p> Signup and view all the answers

Which of the following is a possible interaction of NSAIDs with other drugs?

<p>Decreased antihypertensive effect with β blockers (D)</p> Signup and view all the answers

Which of the following is NOT a therapeutic effect of analgesics?

<p>Cure of the underlying disease causing pain (B)</p> Signup and view all the answers

What is a possible adverse effect of NSAIDs on the renal system?

<p>All of the above (D)</p> Signup and view all the answers

What is the primary difference between opioid and non-opioid analgesics?

<p>Mode of action in the CNS (A)</p> Signup and view all the answers

Which of the following is a characteristic of nonselective COX inhibitors?

<p>They inhibit platelet function (C)</p> Signup and view all the answers

Which of the following NSAIDs is a preferential COX-2 inhibitor?

<p>Celecoxib (A)</p> Signup and view all the answers

What is a possible adverse effect of NSAIDs on the gastrointestinal system?

<p>All of the above (D)</p> Signup and view all the answers

Which of the following is a therapeutic effect of NSAIDs?

<p>Antiinflammatory (A)</p> Signup and view all the answers

What is the mechanism of action of paracetamol?

<p>Unknown, but thought to involve the CNS (B)</p> Signup and view all the answers

Which of the following is a common adverse effect of NSAIDs?

<p>Gastrointestinal bleeding (A)</p> Signup and view all the answers

What is the role of slow-reacting substance of anaphylaxis (SRS-A) in the body?

<p>Mediation of anaphylactic and allergic reactions (B)</p> Signup and view all the answers

Which of the following is an example of a propionic acid derivative NSAID?

<p>Naproxen (A)</p> Signup and view all the answers

What is the role of leukotriene B4 in asthma?

<p>It enhances chemotactic and chemokinetic responses in human neutrophils, monocytes, and eosinophils (C)</p> Signup and view all the answers

What is the effect of COX-1 and COX-2 inhibitors on lipoxygenases?

<p>They inhibit lipoxygenases (B)</p> Signup and view all the answers

What is the therapeutic effect of prostacyclin (PGI2)?

<p>Vasodilation and inhibition of platelet aggregation (A)</p> Signup and view all the answers

What is the function of lipoxin A4 (LXA4)?

<p>Vasodilation and inhibition of neutrophil adhesion and chemotaxis (B)</p> Signup and view all the answers

What is the mechanism of action of aspirin?

<p>Inhibition of COX-1 and COX-2 (A)</p> Signup and view all the answers

What is the therapeutic effect of prostaglandin E2 (PGE2)?

<p>Analgesia and anti-inflammation (B)</p> Signup and view all the answers

What is the effect of leukotriene C4 (LTC4) on the bronchi?

<p>Constriction of the bronchi (C)</p> Signup and view all the answers

What is the effect of thromboxane A2 (TXA2)?

<p>Vasoconstriction and promotion of platelet aggregation (A)</p> Signup and view all the answers

What is the maximum dose of ketorolac that can be administered in a day?

<p>90 mg (C)</p> Signup and view all the answers

What is the percentage of nimesulide bound to plasma proteins?

<p>99% (A)</p> Signup and view all the answers

What is the primary use of nimesulide?

<p>Short-term management of moderate pain (C)</p> Signup and view all the answers

What is a characteristic of nimesulide compared to other NSAIDs?

<p>It is a weak inhibitor of PG synthesis and moderately COX-2 selective (C)</p> Signup and view all the answers

What is a common adverse effect of ketorolac?

<p>All of the above (D)</p> Signup and view all the answers

What is the advantage of selective COX-2 inhibitors compared to traditional NSAIDs?

<p>They cause less gastric mucosal damage (D)</p> Signup and view all the answers

What is the effect of selective COX-2 inhibitors on PGI2 production?

<p>It is decreased (D)</p> Signup and view all the answers

What is the primary action of paracetamol?

<p>Analgesic and antipyretic (A)</p> Signup and view all the answers

Why should selective COX-2 inhibitors be used with caution?

<p>Due to their risk of cardiovascular events (C)</p> Signup and view all the answers

What is the effect of paracetamol on platelet aggregation?

<p>It has no effect on platelet aggregation (D)</p> Signup and view all the answers

What is the plasma half-life of diclofenac?

<p>2 hours (A)</p> Signup and view all the answers

What is a common adverse effect of diclofenac?

<p>Headache (D)</p> Signup and view all the answers

What is the primary use of diclofenac?

<p>Short-lasting painful inflammatory conditions (D)</p> Signup and view all the answers

What is the mechanism of action of diclofenac in terms of COX inhibition?

<p>Somewhat COX-2 selective (A)</p> Signup and view all the answers

What is the dose of diclofenac for short-lasting painful inflammatory conditions?

<p>100 mg BD (D)</p> Signup and view all the answers

What is the percentage of ketorolac excreted unchanged in urine?

<p>60% (D)</p> Signup and view all the answers

Which of the following is a common adverse effect of piroxicam?

<p>Heartburn (B)</p> Signup and view all the answers

What is not a known use of piroxicam?

<p>Hypertension (B)</p> Signup and view all the answers

What is the mechanism of action of ketorolac in relieving pain?

<p>Peripherally acting by inhibiting PG synthesis (C)</p> Signup and view all the answers

What is the plasma half-life of piroxicam?

<p>2 days (B)</p> Signup and view all the answers

Mephenamic acid exerts its analgesic action in which parts of the body?

<p>Both peripheral and central nervous systems (A)</p> Signup and view all the answers

What is a rare but serious complication of Mephenamic acid?

<p>Haemolytic anaemia (A)</p> Signup and view all the answers

What is Piroxicam known for?

<p>All of the above (D)</p> Signup and view all the answers

In which type of pain, is Mephenamic acid primarily indicated?

<p>Muscle and joint pain (A)</p> Signup and view all the answers

What is the dosing frequency of Mephenamic acid?

<p>250-500 mg TDS (D)</p> Signup and view all the answers

What is the primary route of elimination of propionic acid derivatives, including ibuprofen?

<p>Both urine and bile (C)</p> Signup and view all the answers

Which of the following is a contraindication for prescribing ibuprofen?

<p>Pregnancy (D)</p> Signup and view all the answers

What is the primary use of ibuprofen?

<p>Both b and c (C)</p> Signup and view all the answers

What is a common CNS side effect of ibuprofen?

<p>All of the above (D)</p> Signup and view all the answers

How much is the usual dose of ibuprofen?

<p>400-600 mg (B)</p> Signup and view all the answers

What percentage of paracetamol is protein-bound in plasma?

<p>about 1/4 (A)</p> Signup and view all the answers

What is the plasma half-life of paracetamol?

<p>2–3 hours (D)</p> Signup and view all the answers

What is a common adverse effect of paracetamol?

<p>nausea and rashes (D)</p> Signup and view all the answers

In which age group can paracetamol be used?

<p>infants to elderly (C)</p> Signup and view all the answers

What is the dose of paracetamol for children?

<p>10–15 mg/kg (B)</p> Signup and view all the answers

Why is paracetamol preferred over NSAIDs in certain cases?

<p>it does not prolong bleeding time (C)</p> Signup and view all the answers

What is a use of paracetamol?

<p>as an antipyretic (A)</p> Signup and view all the answers

How often should paracetamol be taken?

<p>3–4 times a day (C)</p> Signup and view all the answers

What is the duration of action of paracetamol?

<p>3–5 hours (C)</p> Signup and view all the answers

Why is paracetamol used in pregnant or lactating women?

<p>because it is safer than NSAIDs (B)</p> Signup and view all the answers

Study Notes

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

  • Definition: NSAIDs are a group of drugs that relieve pain, reduce inflammation, and lower fever.
  • Classification:
    • Nonselective COX inhibitors
    • COX-2 inhibitors (e.g. celecoxib, etoricoxib)
    • Preferential COX-2 inhibitors (e.g. nimesulide)
    • Analgesic-antipyretics with poor anti-inflammatory action (e.g. paracetamol)

Mechanism of Action

  • Inhibit cyclooxygenase (COX) enzymes, which convert arachidonic acid to prostaglandins and thromboxane
  • Reduce prostaglandin production, leading to decreased pain and inflammation
  • COX-1 is responsible for platelet aggregation and gastric mucosal protection, while COX-2 is involved in inflammation

Pharmacological Actions of Aspirin

  • Analgesic, antipyretic, and anti-inflammatory effects
  • Irreversibly inhibits thromboxane A2 synthesis, leading to prolonged bleeding time
  • Decreases synthesis of clotting factors in liver, increasing risk of bleeding
  • High doses can cause salt and water retention, vertigo, and tinnitus

Adverse Effects of Aspirin

  • Hypersensitivity and idiosyncrasy
  • Anti-inflammatory doses can cause salicylism, leading to dizziness, tinnitus, and electrolyte imbalance
  • Long-term therapy can cause hepatic injury and Reye's syndrome in children
  • Acute salicylate poisoning can cause coma and death

Features of NSAIDs

  • Nonselective COX inhibitors:
    • Analgesic, antipyretic, and anti-inflammatory effects
    • Increase risk of gastrointestinal bleeding and ulceration
    • May cause renal salt and water retention, and delay or prolong labor
  • COX-2 inhibitors:
    • Analgesic, antipyretic, and anti-inflammatory effects
    • Less gastrointestinal toxicity
    • May increase risk of cardiovascular events

Examples of NSAIDs

  • Salicylates (e.g. aspirin)
  • Propionic acid derivatives (e.g. ibuprofen, naproxen, ketoprofen)
  • Enolic acid derivatives (e.g. piroxicam)
  • Acetic acid derivatives (e.g. ketorolac)
  • Fenamates (e.g. mephenamic acid)
  • COX-2 inhibitors (e.g. celecoxib, etoricoxib)

Pharmacokinetics and Interactions

  • NSAIDs are well absorbed orally, metabolized in the liver, and excreted in the urine
  • May interact with other medications, such as diuretics, anticoagulants, and antihypertensives
  • May cause displacement interactions due to high protein binding

Contraindications and Precautions

  • NSAIDs are contraindicated in patients with active peptic ulcer, bleeding disorders, and hypersensitivity
  • Use with caution in patients with cardiovascular disease, hypertension, and kidney disease
  • Avoid use in pregnant women, especially in the third trimester

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Description

This quiz covers the interactions between different medications, including oral anticoagulants, sulfonylureas, and more. Learn about the risks and effects of combining these drugs.

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